Background: Primary care physician (PCP) shortages are a significant and growing problem confronting the US healthcare system. An overall shortage of up to 53,000 PCPs is projected in the US by 2025, due in part to increased demand for primary care services because of an aging population, growing disease burden and a declining interest in primary care careers among medical residents. A shortage of PCPs in VA has recently come under increased focus due to the emphasis on improving Veterans? access to high quality and timely healthcare. Providing timely access to primary care requires a sufficiently large PCP workforce. However, as of May 2016, VA was reported to have been trying to fill up to 500 PCP positions, reflecting roughly 12% of the current VA PCP workforce. Prior research has not examined several important individual, economic, job and system-level factors associated with the recruitment and retention of PCPs by health systems. These understudied factors include components of pay and compensation, academic affiliation, elements of the patient-centered medical home model and workplace climate, which represent areas where VA data offer unique contributions. In addition, no prior research has examined the relative importance of factors in explaining PCP recruitment and retention. Identifying and prioritizing key factors associated with PCPs? employment choices will help VA and other health systems with the strategic recruitment of PCPs and the development of evidence-based strategies to retain high quality PCPs. Objectives: The objectives of this study are to: 1) identify and prioritize individual, job, economic and system- level factors associated with the choice of VA for employment and selection of rural practice (i.e. recruitment) using existing VA data as well as new qualitative and survey data collected for this study and 2) identify and prioritize individual, job, economic and system-level factors associated with long-run retention of PCPs within VA and in rural VA clinics using administrative data and existing survey data. Methods: This mixed methods study will examine VA administrative data, existing VA employee survey data, public health resource data and new qualitative and survey data collected for this project. To measure factors associated with VA recruitment and choice of rural practice setting (Aim 1), we will conduct structured interviews with current internal medicine residents exposed to VA settings during their training and new PCPs with a permanent VA position. We will then develop and administer a new survey instrument using key factors identified in qualitative interviews and factors of particular interest in this study. Triangulation will then be used to assess whether key factors and themes established in qualitative analyses generalize to the larger population of internal medicine residents and new VA PCPs. We will perform descriptive analyses to compare influential factors identified in interviews and surveys between residents and new PCPs. Multivariable analyses will be used to identify factors that are significantly associated with consideration of VA employment and rural practice among internal medicine residents. For Aim 2, we will use VA administrative databases to track the employment status of VA PCPs longitudinally. We will identify all PCPs assigned to a panel of primary care patients who met a minimum clinical full-time equivalent (FTE) threshold and were employed by VA at any time during the period 2003-2016. We will link administrative data with VA and public survey data to examine key factors of interest. Statistical methods for survival data analysis will be applied to assess the influence of hypothesized factors on quarterly retention probabilities and PCPs? expected duration of VA employment. Parallel analyses will assess PCP retention in rural VA facilities. Secondary analyses will examine the longitudinal profile of clinical FTE using an extended two-part model. In both aims, we will apply econometric methods including Shapley value decompositions to partition the variation in PCP recruitment and retention explained by key explanatory factors and factor combinations.